Publikation
Ibañez, C.; Poeschl, Y.; Peterson, T.; Bellstädt, J.; Denk, K.; Gogol-Döring, A.; Quint, M.; Delker, C. Ambient temperature and genotype differentially affect developmental and phenotypic plasticity in Arabidopsis thaliana BioRxiv (2017) DOI: 10.1101/017285
Background: Global increase in ambient temperatures constitute a significant challenge to wild and cultivated plant species. Forward genetic analyses of individual temperature-responsive traits have resulted in the identification of several signaling and response components. However, a comprehensive knowledge about temperature sensitivity of different developmental stages and the contribution of natural variation is still scarce and fragmented at best. Results: Here, we systematically analyze thermomorphogenesis throughout a complete life cycle in ten natural Arabidopsis thaliana accessions grown in four different temperatures ranging from 16 to 28 °C. We used Q 10 , GxE, phenotypic divergence and correlation analyses to assess temperature sensitivity and genotype effects of more than 30 morphometric and developmental traits representing five phenotype classes. We found that genotype and temperature differentially affected plant growth and development with variing strengths. Furthermore, overall correlations among phenotypic temperature responses was relatively low which seems to be caused by differential capacities for temperature adaptations of individual accessions. Conclusion: Genotype-specific temperature responses may be attractive targets for future forward genetic approaches and accession-specific thermomorphogenesis maps may aid the assessment of functional relevance of known and novel regulatory components.
Publikationen in Druck
Drost, H.-J.; Gabel, A.; Domazet-Lošo, T.; Quint, M.; Grosse, I. Capturing Evolutionary Signatures in Transcriptomes with myTAI BioRxiv (2016) DOI: 10.1101/051565
Combining transcriptome data of biological processes or response to
stimuli with evolutionary information such as the phylogenetic
conservation of genes or their sequence divergence rates enables the
investigation of evolutionary constraints on these processes or
responses. Such phylotranscriptomic analyses recently unraveled that
mid-developmental transcriptomes of fly, fish, and cress were dominated
by evolutionarily conserved genes and genes under negative selection and
thus recapitulated the developmental hourglass on the transcriptomic
level. Here, we present a protocol for performing phylotranscriptomic
analyses on any biological process of interest. When applying this
protocol, users are capable of detecting different evolutionary
constraints acting on different stages of the biological process of
interest in any species. For each step of the protocol, modular and
easy-to-use open-source software tools are provided, which enable a
broad range of scientists to apply phylotranscriptomic analyses to a
wide spectrum of biological questions.
Publikation
Trenner, J.; Poeschl, Y.; Grau, J.; Gogol-Döring, A.; Quint, M.; Delker, C. Auxin-induced expression divergence between Arabidopsis species likely originates within the TIR1/AFB-AUX/IAA-ARF module BioRxiv (2016) DOI: 10.1101/038422
Auxin is an essential regulator of plant growth and development and
auxin signaling components are conserved among land plants. Yet, a
remarkable degree of natural variation in physiological and
transcriptional auxin responses has been described among Arabidopsis
thaliana accessions. As intra-species comparisons offer only limited
genetic variation, we here inspect the variation of auxin responses
between A. thaliana and A. lyrata. This approach allowed the
identification of conserved auxin response genes including novel genes
with potential relevance for auxin biology. Furthermore, promoter
divergences were analyzed for putative sources of variation. De novo
motif discovery identified novel and variants of known elements with
potential relevance for auxin responses, emphasizing the complex, and
yet elusive, code of element combinations accounting for the diversity
in transcriptional auxin responses. Furthermore, network analysis
revealed correlations of inter-species differences in the expression of
AUX/IAA gene clusters and classic auxin-related genes. We conclude that
variation in general transcriptional and physiological auxin responses
may originate substantially from functional or transcriptional
variations in the TIR1/AFB, AUX/IAA, and ARF signaling network. In that
respect, AUX/IAA gene expression divergence potentially reflects
differences in the manner in which different species transduce identical
auxin signals into gene expression responses.
Publikation
Raschke, A.; Ibañez, C.; Ullrich, K. K.; Anwer, M. U.; Becker, S.; Glöckner, A.; Trenner, J.; Denk, K.; Saal, B.; Sun, X.; Ni, M.; Davis, S. J.; Delker, C.; Quint, M. Natural Variants of ELF3 Affect Thermomorphogenesis by Transcriptionally Modulating PIF4-Dependent Auxin Response Genes BioRxiv (2015) DOI: 10.1101/015305
Perception and transduction of temperature changes result in altered
growth enabling plants to adapt to increased ambient temperature. While
PHYTOCHROME-INTERACTING FACTOR4 (PIF4) has been identified as a major
ambient temperature signaling hub, its upstream regulation seems complex
and is poorly understood. Here, we exploited natural variation for
thermo-responsive growth in Arabidopsis thaliana using quantitative
trait locus (QTL) analysis. We identified GIRAFFE2.1, a major QTL
explaining ~18% of the phenotypic variation for temperature-induced
hypocotyl elongation in the Bay-0 x Sha recombinant inbred line
population. Transgenic complementation demonstrated that allelic
variation in the circadian clock regulator EARLY FLOWERING3 (ELF3) is
underlying this QTL. The source of variation could be allocated to a
single nucleotide polymorphism in the ELF3 coding region, resulting in
differential expression of PIF4 and its target genes, likely causing the
observed natural variation in thermo-responsive growth. In combination
with other recent studies, this work establishes the role of ELF3 in the
ambient temperature signaling network. Natural variation of
ELF3-mediated gating of PIF4 expression during nightly growing periods
seems to be affected by a coding sequence quantitative trait nucleotide
that confers a selective advantage in certain environments. In
addition, natural ELF3 alleles seem to differentially integrate
temperature and photoperiod cues to induce architectural changes. Thus,
ELF3 emerges as an essential coordinator of growth and development in
response to diverse environmental cues and implicates ELF3 as an
important target of adaptation.
Publikation
Drost, H.-G.; Bellstädt, J.; Ó'Maoiléidigh, D. S.; Silva, A. T.; Gabel, A.; Weinholdt, C.; Ryan, P. T.; Dekkers, B. J. W.; Bentsink, L.; Hilhorst, H. W. M.; Ligterink, W.; Wellmer, F.; Grosse, I.; Quint, M. Post-embryonic hourglass patterns mark ontogenetic transitions in plant development BioRxiv (2015) DOI: 10.1101/035527
The historic developmental hourglass concept depicts the convergence of
animal embryos to a common form during the phylotypic period. Recently,
it has been shown that a transcriptomic hourglass is associated with
this morphological pattern, consistent with the idea of underlying
selective constraints due to intense molecular interactions during body
plan establishment. Although plants do not exhibit a morphological
hourglass during embryogenesis, a transcriptomic hourglass has
nevertheless been identified in the model plant Arabidopsis thaliana.
Here, we investigated whether plant hourglass patterns are also found
post-embryonically. We found that the two main phase changes during the
life cycle of Arabidopsis, from embryonic to vegetative and from
vegetative to reproductive development, are associated with
transcriptomic hourglass patterns. In contrast, flower development, a
process dominated by organ formation, is not. This suggests that plant
hourglass patterns are decoupled from organogenesis and body plan
establishment. Instead, they may reflect general transitions through
organizational checkpoints.
Publikation
Abel, S.; Savchenko, T.; Levy, M. Genome-wide comparative analysis of the <em>IQD</em> gene families in <em>Arabidopsis thaliana</em> and Oryza sativa BMC Evolutionary Biology 5, 72 (1-25), (2005)
We identified and analyzed 33 and 29 IQD1-like genes in Arabidopsis thaliana and Oryza sativa, respectively. The encoded IQD proteins contain a plant-specific domain of 67 conserved amino acid residues, referred to as the IQ67 domain, which is characterized by a unique and repetitive arrangement of three different calmodulin recruitment motifs, known as the IQ, 1-5-10, and 1-8-14 motifs. We demonstrated calmodulin binding for IQD20, the smallest IQD protein in Arabidopsis, which consists of a C-terminal IQ67 domain and a short N-terminal extension. A striking feature of IQD proteins is the high isoelectric point (~10.3) and frequency of serine residues (~11%). We compared the Arabidopsis and rice IQD gene families in terms of gene structure, chromosome location, predicted protein properties and motifs, phylogenetic relationships, and evolutionary history. The existence of an IQD-like gene in bryophytes suggests that IQD proteins are an ancient family of calmodulin-binding proteins and arose during the early evolution of land plants. Comparative phylogenetic analyses indicate that the major IQD gene lineages originated before the monocot-eudicot divergence. The extant IQD loci in Arabidopsis primarily resulted from segmental duplication and reflect preferential retention of paralogous genes, which is characteristic for proteins with regulatory functions. Interaction of IQD1 and IQD20 with calmodulin and the presence of predicted calmodulin binding sites in all IQD family members suggest that IQD proteins are a new class of calmodulin targets. The basic isoelectric point of IQD proteins and their frequently predicted nuclear localization suggest that IQD proteins link calcium signaling pathways to the regulation of gene expression. Our comparative genomics analysis of IQD genes and encoded proteins in two model plant species provides the first step towards the functional dissection of this emerging family of putative calmodulin targets.
Publikation
Berger, S.; Weichert, H.; Porzel, A.; Wasternack, C.; Kühn, H.; Feussner, I. Enzymatic and non-enzymatic lipid peroxidation in leaf development Biochim. Biophys. Acta 1533, 266-276, (2001)
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